Psoriatic Arthritis: All You Need to Know


Psoriatic Arthritis: All You Need to Know

Elderly man suffering from psoriasis, closeup on hands

If you have psoriasis, you already know that this chronic skin disorder can be both uncomfortable and inconvenient. But you might not realize that having psoriasis is also a risk factor for psoriatic arthritis, a rheumatologic condition that could severely damage your joints if left untreated.  

Symptoms may emerge in large or small joints, such as the shoulders, spine, knees, pelvis, fingers and/or toes. A Rheumatologist can provide treatment for patients with psoriatic arthritis, to help them manage inflammation, flare ups, and pain, and minimize the chance of long-term disability.  

Psoriatic Arthritis Explained 

“Between 20-30% percent of people with longstanding plaque psoriasis will develop inflammation in the joints similar to rheumatoid arthritis,” said Dr. Jeff Peterson, rheumatologist at WWMG. Less common than rheumatoid arthritis, psoriatic arthritis is a chronic inflammatory disease that affects joints and the points where tendons and ligaments connect to bones.  

“It can be quite destructive, and it can be more aggressive than rheumatoid arthritis and lead to complete joint destruction, in some people in a matter of months to a couple years,” said Peterson. 

Psoriatic arthritis occurs equally among all genders and can appear at any age. Although it can occur in people who have never experienced psoriasis, 90% of psoriatic arthritis patients also have psoriasis.  

It is more common in people who have psoriasis on their scalp or fingernails. Sometimes both conditions appear for the first time together. Psoriatic arthritis is most likely to occur in the peripheral joints – that is, joints of the arms and legs – but can occur in the spine, hips, and shoulders as well.  


As with other types of arthritis, psoriatic arthritis can progress without symptoms for a long time before causing flare-ups.  

Primary symptoms of psoriatic arthritis include: 

  • Pain  
  • Stiffness, and 
  • Swelling 

When the arthritis occurs in the joints, tenderness is accompanied by pronounced swelling.  

“You can get what we call a sausage digit – an entire finger or toe that is so swollen it can’t bend very well,” said Peterson. Other forms of arthritis, like gout, are more likely to affect a single knuckle than the entire digit.  

When it occurs between the joints of the spine or around the pelvis, psoriatic arthritis causes low back pain and stiffness, especially in the morning. In contrast to low back pain caused by injury, the pain with psoriatic arthritis usually improves after activity. 

Because this type of arthritis is so painful, most people don’t hesitate to seek treatment. But even if you’re reluctant, it’s important not to ignore a flare-up. Some forms of psoriatic arthritis are very aggressive and can destroy a joint in a matter of months.  

Getting a Diagnosis for Psoriatic Arthritis 

For a diagnosis, usually a primary care provider or dermatologist will refer the patient to a rheumatologist. If you have psoriasis or a family history of either psoriasis or psoriatic arthritis, you should ask for a referral to a rheumatologist – don’t wait for your primary care provider to suggest it. 

“Family history and clinical examination are key for diagnosing this disease,” said Peterson. Although it presents similarly to rheumatoid arthritis, psoriatic arthritis is asymmetric, meaning it can affect a joint on one side of the body but not the other, or it may affect different joints on each side of the body.  

Joint damage is identified through X-ray imaging, ultrasound, or advanced imaging such as an MRI or CT scan. 

“You can tell psoriatic arthritis from rheumatoid arthritis by its characteristic new bone growth at the joints. Areas where the tendon attaches to bone become calcified and then you get erosion underneath it in what we call a pencil and cup deformity,” said Peterson. Rarely, a genetic test may be used to look for the HLA-B27 marker, which is strongly associated with the condition.  


Roughly 20% of psoriasis sufferers will develop psoriatic arthritis. While both psoriasis and arthritis are inflammatory diseases, the exact connection between them is not understood.  

Because the cause of psoriatic arthritis is unknown, there is no way to prevent the disease. But patients can take steps to prevent triggering expression of the HLA-B27 gene.  

“Cells that are activated then collect around the tendon insertion and cause inflammation in that area, leading to calcification and the erosion underneath,” said Peterson. Although calcification is what damages the joint, inflammation is what causes the pain.  

Lifestyle Changes Can Reduce Flare-Ups 

Lifestyle choices that minimize inflammation are a good idea for everyone but they are especially important for people with a family history of psoriasis and arthritis. Stress management and low impact exercise like swimming or tai chi are recommended when it’s not too painful.  

“Every study suggests that light exercise is good for inflammatory arthritis,” said Peterson. A diet that avoids pro-inflammatory foods like sugar and high fructose corn syrup can also help prevent flare ups.  


Psoriatic arthritis is chronic and incurable, but early and ongoing treatment can prevent flare ups, manage pain, and minimize joint damage.  

“We can control it, that’s the good news. There’s lots of choice for therapeutic control,” said Peterson. Although many people dislike the idea of taking medicine for life, it is necessary for psoriatic arthritis. Without medication, joints will continue to degenerate in between flare ups.  

“Once the joint is gone, if you’ve lost function, say range of motion or strength, you can’t repair it,” warns Peterson. Fortunately, several different drug classes can treat psoriatic arthritis effectively. The type and dosage depend on a variety of factors. Patients may take a daily pill, receive a weekly injection, or visit WWMG’s infusion center quarterly or at a frequency recommended by the treating rheumatologist. 

“At my clinic, we are interested in a more holistic approach. So, not only do we use the regular medications at our disposal, we also feel it is helpful to work with a patient’s primary care provider or naturopathic doctor to support diet and lifestyle changes,” said Peterson. Lifestyle changes may not completely eliminate the need for medication, but can help reduce the dosage and minimize flare-ups.   

“Early treatment will prevent permanent damage,” said Peterson. If you have psoriasis and begin experiencing joint pain, do not delay talking to your primary care provider or dermatologist for a rheumatology referral. WWMG’s Rheumatology providers see patients in Bothell, Silver Lake, and Everett. Contact us to request an appointment with a Rheumatologist today.